It's crunch time for Tampa's homegrown biomedical institute, M2Gen, a place with expectations so high, helping to beat cancer is only one goal. Hillsborough County, Tampa and the state have pumped about $45 million in subsidies into this unit of H. Lee Moffitt Cancer Center & Research Institute, hoping it would create high-paying jobs and build a biomedical industry here. So far, no such industry has really sprouted up around M2Gen. And, it could face a huge challenge if it loses its biggest financial supporter, the drug giant Merck.